Interlocking control apparatus



April ,1941. E. M. ALLEN ETAL 2,237,804

INTERL OCKING CONTROL APPARATUS Original Filed April 5, 1955 8 Sheets-Sheet l w Mb 59 95 11' mmmms Earl M. Allen and By Howami A. Thoq som. 9 1' 6? WW THEIR ATTORNEY April 8, 1941. M ALLEN ETAL 2,237,$@4

INTERLOCKING CONTROL APPARATUS Original Filed April 5, 1935 8 Sheets-Sheet 5 P- c 4 11 133 1 Q3 0 1 g? 5 4 lizr a2? m wZE/Q I IN VENT ORS Earl M. Allen and y Howard A, Thom zyon.

THEIR A TTORNEY April 8, 1941. i E. M. ALLEN ETAL 2,237,804

INTERLOCKING CONTROL APPARATUS Original Filed April 5, 1935 8 Sheets-Sheet 4 Earl M. Allen and y Howard A. Thom son.

VFW THEIR ATTORNEY April 8, 1941. E. M. ALLEN ETAL INTERLOCKING CONTROL nmmwus Original Filed April 5, 1935 8 Sheets-Sheet 5 A TTORNE Y g mi INVENTORS Earl M. Allen and, BY Howard A Thom Qzmfi THEIR TIL 5N mm Q mm E. M. ALLEN ETAL INTERLOCKING CONTROL APPARATUS April 8, 1941.

Original Filed April 5, 1935 8 Sheets-Sheet S d Y an f E R mi N fin mmzm m T. Q AA R 1mm wwwm E a :3 am m m T i wt Rm lmww mu M ng J K Q WWW N M. MGM. EMNWQMJ a m MN Es NQ mam n @uNgg @Kfi Wm MEN wa h fi April 1941- E. M. ALLEN HAL 2.237.804

INTERLOCKING CONTROL APPARATUS Original Filed April 5, 1935 8 Sheets-Sheet 7 I i 51 x4 mg 1 41: Y4a :i x

g 5 4 4 w 26% i 257P 21Y5 224Y6 23X5-6 M -5-6 14YIZ 17b 1/10 x1 mmvrozas Earl M Allen and BY Howard A. Tham son.

W THEIR ATTORNEY April 8, 1941. M ALLEN ETAL 2,237,804 v INTERLOCKING CONTROL APPARATUS Original Filed April 5 1935 8 Sheets-Sheet 8 i 8 MW 7 Q N MS Q RN MKNN. wNM (A 3M mma EN ENS NE m n m W\N% N\N% Q m R R NM m? E w& 13 5 53 g k 9% RN ew? Patented Apr. 8, 1941 INTER-LOCKING CONTROL APPARATUS Earl M. Allen, Swissvale, and Howard A. Thompson, Wilkinsburg, Pa., assignors to The Union Switch & Signal Comp any, Swissvale, Pa., a corporation of Pennsylvania Application April 5, 1935, Serial No. 14,868 Renewed August 22, 1936 45 Claims. (Cl. 246-134) Our invention relates to interlocking control apparatus, and is particularly adapted for, though not limited to, the control of railway track switches and signals in a railway switching or interlocking layout.

vided for a similar purpose. In this form a por- One feature of our invention is the provision of novel and improved interlocking control apparatus without the use of interlocked levers, which is an improvement upon the system shown in our Patent No. 2,184,787, granted December 26, 1939. Another feature of our invention is the provision of novel and improved indication apparatus associated with such interlocking control apparatus.

More particularly, the principal object of our invention is the provision of a system of route interlocking of the entrance-exit type in which the switches and signals are controlled by route buttons or miniature levers associated with the entrance and exit ends of the different routes,

which is an improvement upon that shown in the United States application Serial No. 726,957, filed May 22, 1934 by L. E. Spray, for Interlocking control apparatus.

3 In the system of this prior application, a control board is provided which contains a minia-' ture diagram of the track layout to 'be controlled, with the route buttons mounted thereon at points corresponding with the ends of the routes. Electroresponsive route selecting means is provided which responds to the joint operation of the buttons for the entrance and exit ends of an available route, to automatically operate the track switches to the positions required to set up such route and to then clear the signal at its entrance.

The system of our invention functions in a similar manner, and one object of our invention is to facilitate these operations by the provision of an improved track diagram in which the tracks are illuminated to indicate the condition of a proposed or established route. In one form of our invention miniature lamps mounted in the tracks of the diagram are so controlled that a row of lamps selected by the operation of the buttons for the two ends of a route is lighted to distinctively mark the route on the track diagram, so as to indicate the condition of occupancy of each track section and the position of each track switch of the route, as well as the location of the entrance signal for the route. In

another form of our invention substantially lintion of track in the diagram for each unoccupied track section of a route becomes illuminated in response to the operation of the corresponding route buttons to indicate a proposed route, short linear portions each of which represents a track switch of the route become illuminated as the switches assume the required positions and the portion representing the entrance signal becomes illuminated when the route is fully established, so "that a completed route is indicated by a substantially continuous illuminated line.

A feature of our invention is the inclusion in ie circuits by which the buttons control the electroresponsive route selecting means for setting up the routes, of indication relays and control contacts therefor, for controlling the lamps of the track diagram, and of route relays for controlling the signals in addition to those provided for controlling the track switches, in order to simplify the circuits required.

Another featur of our invention resides in the control of the route selecting means by buttons of the rotary type with the circuits so arranged that a route may also be set up and its representation illuminated on the track diagram without clearing the signal at either end. Other features comprise the provision of auxiliary push buttons for operating each track switch or crossover individually, and other push buttons for designating which of two routes is to be set up by the operation of the route levers when the track layout provides two alternative routes between the same route ends.

Our invention also includes an improved arrangement for locking the track switches wherein the route relays for establishing a route govern switch locking relays provided to prevent operation of the track switches except when conditions are proper. In accordance with our invention the locking relays for the switches of a route release as soon as the route is set up to thereby lock the switches in the required position, this operation being checked by making the clearing of the entrance signal dependent upon the release of these locking relays.

We will describe two forms of apparatus em bodying our invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1 l 2 2 and 4 to 9, inclusive, are diagrammatic views showing the component parts of one form of apparatus embodying our invention. More specifically, Figs. 1 and 1', when placed side by side,

, with Fig. 1 on the left, show a typical track,

switch, and signal layout, as well as switch control and indication circuits for apparatus embodying our invention; Figs. 2 and 2 when placed side by side, with Fig. 2 on the left, show a track model and interlocking control board for the layout shown in Figs. 1 and 1; Fig. 4 shows circuits for the operation of normal and reverse stick control relays for the track switches; Figs. 5* and 5*, when placed end to end, with Fig. 5 on the left, show route selection circuits controlled by manual devices on the control board of Figs. 2* and 2; Figs. 6 and 6*, when placed end to end, with Fig. 6 on the left, show a signal selection circuit network; Fig. 7 shows approach locking and release circuits for the track switches, and also shows call-on signal control circuits; Fig. 8 shows signal slotting relay circuits; and Fig. 9 shows a signal control relay network. Fig. 3 is a diagrammatic view showing a modification of the track model and interlocking control board of Figs. 2 and 2 for use in apparatus embodying our invention.

Similar reference characters refer to similar parts in each of the views.

Referring first to Figs. 1 and 1*, these draw ings show a track layout comprising a plurality of track sections interconnected by track switches to form different traffic routes. As illustrated, the layout consists of a stretch of double track railway, tracks ac and DD of which are interconnected through a crossover ee with which they are respectively joined by switches H and H and are likewise interconnected by a crossover ff with which they are respectively joined by switches H and H Tracks ma and bb are also respectively joined to passing sidings cc and dd by switches H and H The reference characters I and l designate the rails of track ad, and the reference characters 2 and 2 designate the rails of track bb.

These rails are divided by insulated joints 3 to form a plurality of track sections a -A, Aii, ii7 7';iE, EE B B, B-mm, mm-G, G-D, Dd and (l -d Each of these track sections is supplied with current by a battery 4 connected across the rails adjacent one end of the section. A track relay, designated by the reference character T with a distinguishing exponent,'is connected across the rails adjacent the opposite end of each track section.

Each track section in which a switch is located will be referred to hereinafter as a detector section. Track section aA in the rear of signals S track sections D-d and (l -d in the rear of signals S and track sections 13 -3 and E---E in the rear of signals S and S respectively, will be referred to as approach sections.

Each of the approach and detector track section relays T to T inclusive, when deenergized, controls energization of a slow-releasing relay designated by the reference character 22 with an exponent corresponding to that of the track relay by which it is controlled. Each of the track relays T to T inclusive, together with its associated slow-releasing relay b, controls a repeater relay designated by the reference character p with an exponent corresponding to that of the track relay by which it is controlled. A similar repeater relay 12 is controlled by track relays T and T and by the associated slowreleasing relays b and b. Each of the track relays T is provided with a stick circuit including one of its own front contacts 39, and has a pickup circuit controlled by a front contact 40 of its 7 associated slow-releasing relay b, as shown for relays T T T and T The repeater relay p, associated with the track relay T for the first track section in advance of each of the groups of signals S and 8, controls, in part, a repeater stick relay designated by the reference character U with an exponent corresponding with that of the repeater relay by which it is controlled.

Reference character S, with distinguishing exponents, designates signals which are placed at the entrances to the different routes adjacent the points A, B, C, D, E and F, respectively, and which as here shown are of the semaphore type. Signals S S and S are mounted on a common mast I0, and signals S S and S are mounted on a common mast 9. Signals S S S S and S govern eastbound traffic movements, that is, movements which are made over the stretch of track from left to right as shown in the drawings, and signals S S S, S and S govern westbound traffic movements, that is, movements which are made over the stretch of track from right to left as shown in the drawings.

Between the group of eastbound signals and the group of westbound signals, eleven different routes may be established according to the position of the various switches. Over each of these routes, traflic can proceed in either direction, that is, from west to east, or from east, to west, as controlled by a signal for each direction of traflic over each route.

The arrangements of the switches for these various routes are as given in the following table:

Route 1.A to E, switches H H and H normal.

Route 2.A to F, switches H and H normal,

and H reversed.

Route 3.A to D, switches H and H reversed,

and I-I normal.

Route 4.A to E, switches H H H and H5 reversed, and H normal.

Route 5.-A to F, switches H H, H H and H reversed.

Route 6.B to D,

mal.

Route 7.-B to E, switches H H and H normal, and H and H reversed.

Route 8.B to F, switches H and H normal,

and H H and H reversed.

Route 9.-C to D, switch H reversed, and'switches H and H normal.

Route 10.-C to E, switches H H and H reversed, and H and H normal.

Route 11.C to F, switches H H H and H reversed, and H normal.

switches H H and H nor- Each switch H is operated by a motor designated by the reference character M with an ex ponent corresponding with that of the reference character H for the switch. Each motor M may be of a fluid pressure type which is provided with a normal control magnet nn, a reverse control magnet T1, and a master control or lock magnet q.

Normal and reverse control magnets on and T1 for motor M for operating switch H are controlled by a neutral contact H of a polarized switch control relay m and by a polar contact 12 of the same relay in its normal or its reverse position, respectively. Lock magnet q for motor M is controlled by back contacts of normal and reverse indication relays designated by the reference characters i and t respectively. The control circuits for the motor of switch H are similar to those for motor M and are therefore omitted from the drawing.

Normal and reverse control magnets on and mfor motors M and M for operating switches H and H, respectively, of crossover If are controlled, with the normal magnets mt in series, and with the reverse magnets M" in series, by a polar contact I2 in its normal or its reverse position, and by a neutral contact These are contacts of a polarized switch control relay m Lock magnets q for motors M and M are controlled in series by back contacts of normal and reverse indication relays i and t respectively. The control circuits for the motors for operating switches H and H of crossover ee are similar to those for motors M and M and are therefore not shown in the drawings.

Operated in conjunction with switch H is a pole-changer 5. A similar pole-changer is operated in conjunction with switch H Operated in conjunction with switches H and H are polechangers ii and 5, respectively. Similar polechangers are operated in conjunction with switches H and H respectively.

A polarized switch indication relay 72 is so controlled by pole-changer 5 of switch H that it becomes energized in the normal or the reverse direction according as switch H is operated to, and locked in, its normal or its reverse position, respectively. A second polarized switch indication relay h is similarly controlled in conjunction with switch H and its control circuits are therefore omitted from the drawing. A third polarized switch indication relay I1 is so controlled by a circuit including pole-changers 6 and l of switches H and H, respectively, in series that it becomes energized in the normal or the reverse direction according as switches H and H are operated to, and locked in, their normal or reverse positions, respectively. A fourth polarized switch indication relay h is similarly controlled in conjunction with switches H and H, and its control circuits are therefore omitted from the drawing.

A normal indication circuit controller shown as a relay designated by the reference character 1', and a reverse indication circuit controller shown as a relay designated by the reference character t, are associated with each single switch or pair of crossover switches, and are distinguished by exponents corresponding to those of the corresponding switches. Each relay z' is controlled by a neutral front contact and by a normal polar contact of the polarized indication relay h and of the polarized control relay m for its switch, as well as by a back contact of the reverse indication relay t for the same switch. Each relay t is controlled by a neutral front and a reverse polar contact of the polarized indication relay h and of the polarized control relay m for its switch, as well as by a back contact of the normal indication relay 2 for the same switch.

Each switch control relay in is controlled by a. lock relay designated by the reference character R with an exponent corresponding to that of the associated switch, and by normal and reverse switch control stick relays designated by the reference character a with exponents including the letters 12 and 1", respectively, and also including numbers corresponding to the exponents for the associated switches. A resistor 75 is connected in multiple with the winding of each relay m in order to make the relay m slow in releasing.

Control circuits for relays z are shown in Fig. 4. a

Each lock relay R is controlled by the associated polarized switch control relay m, and by the associated normal and reverse switch control stick relays 2n and 21", respectively, as well as by a repeater relay 1) or by both a repeater relay p and a repeater stick relay U and by an approach locking relay designated by the reference character P with a distinguishing exponent, shown in Fig. 7, and also by one or more route locking relays designated by the reference character V with a distinguishing exponent.

Each route locking relay V is so controlled that it becomes deenergized when an approach locking relay P for a route which it controls is deenergized. Each relay V can then be reenergized if the associated relay P is again energized before a train enters its: route at the signal. Each relay V, after a train enters its route while its associated signal is indicating proceed, can be reenergized only after the train has left a given portion of its route.

In each of the drawings, the contacts operated by the various relays or by the time release J, or by other control devices including the control levers and push buttons shown in Figs. 2 and 3, are identified by numbers, such numbers having distinguishing exponents when the contacts are shown elsewhere than adjacent the respective relay or release or other control device by which they are operated. The exponent for each of these contact numbers comprises the reference character and exponent for the re spective relay, release, or other control device by which the associated contact is operated. For example, the exponent p for contact Hit? shown in a circuit for relay V in Fig. l comprises the reference character 12 and its exponent 2 for repeater relay p which operates contact IEBQ Similarly, exponent V for contact shown in the circuit for relay R in Fig. 1 comprises reference character V and its exponent 3 for relay V which operates contact Two groups of contacts are shown for time release J in Fig. 7. Different types of con tacts operated by release J are distinguished by the exponents a and b, and the contacts of release J which are shown in Fig. 7 associated with relays P and P and which are shown separately from release J, have the additional exponent character J.

In Figs. 2 and 2 a combined track diagram or track model and interlocking control board is shown on which the locations of the representations of signals S with respect to the track diagram correspond to the locations of the signals with respect to the tracks shown in Figs. 1 and l Indicator lamps, each of which is designated by the reference character e with an exponent comprising the reference character and exponent of the signal, are shown adjacent the corresponding signal representations. Other indicator lamps, each of which is designated by the reference character e with an exponent comprising the reference character and exponent of a track switch I-I together with the letter 11 or 1' indicating normal and reverse, respectively, are shown in the corresponding positions of the associated switches. Still other indicator lamps, each of which is designated by the reference character 6 with an exponent indicative of a track section with which it is associated, are shown in the track diagram in locations corresponding to the locations of the associated track sections.

Indicator lamps e associated with signals, switches, and the detector track sections are controlled by indication relays k which are in turn controlled as shown in Fig. 5. Indicator lamps 6 associated with approach track sections are controlled by back contacts of repeater relays p which are controlled as already stated in connection with Figs. 1 and l Manually operable devices, designated by the reference character K with distinguishing exponents, are disposed on the control board adjacent points A, B, C, D, E and F. Devices K may be rotatable levers each having a normal position 11, a reverse position to the left '0, and a reverse position to the right 1. Manually operable push buttons w and w, shown adjacent the representations of signals S and 8, respectively, are for the call-on control of these signals. Manually operable push buttons w and w are used to provide for run-around train movements past point G. Normal and reverse manual control contacts designated by the reference character a with the exponents of the switches and the letter 11 or r to indicate normal and reverse, respectively, are shown adjacent the representation of each single switch and adja cent the representations of one switch of each crossover for individually controlling the associated single switches and crossovers.

Fig. 3 shows a modification of the track model and interlocking control board of Fig. 2, in which the lamps e of Fig. 2 which are associated with the track sections and switches are replaced by substantially linear but separate light sources such as neon gas tubes each designated by the reference character with an exponent corresponding to that of the lamp e of Fig. 2. The energization of the neon gas tubes 0 is controlled in the same way as the lighting of the corresponding lamps e of Fig. 2.

As shown in Fig. 4, normal switch control stick relay 2 for controlling operation of switch H to the normal position has a stick circuit controlled by a back contact of the associated reverse switch control stick relay z", and has a pick-up circuit controlled by a front contact of a normal switch route relay designated by the reference character 1 with the exponent l corre sponding to that of the associated switch H Control circuits for relays f are shown in Fig. Relay 2 has also a pick-up circuit controlled by normal manual control contact u shown in Figs. 2 and 3. Reverse switch control relay z" for controlling operation of switch H to the reverse position has a stick circuit controlled by a back contact of relay 2", and has pick-up circuits controlled by reverse switch route relay g circuits for which are shown in Fig. 5 and by reverse manual control contact u shown in Figs. 2 and 3. The control circuits for normal and reverse stick relays 2 and 2 for switch H are similar to those shown for relays a and a, respectively, and are therefore omitted from the drawing. The control circuits for relay e are similar to those for relay 2 except that an additional pick-up circuit is provided which is controlled by a second normal switch route relay f for switches 1-1 and H The control circuits for relay z are similar to those already described for relay z. The control circuits for normal and reverse control stick relays 2 and 2 for switches H and H are similar to those which are shown for relays 2 and 2 respectively, and are therefore omitted from the drawings,

In Figs. 5 and 5 route selection circuits are shown controlled by the manually controlled devices or levers K, and by push buttons w and w of Figs. 2 and 3. Each of these route selection circuits corresponds to a given route, and includes contacts operated by levers K for the two ends of the route, a contact controlled by push button w or w, the winding of a route stick relay 1 or y, the winding of a normal or a reverse switch route relay f or g, respectively, for each switch in the route, and either the winding of an indication relay is together with an associated indication front contact or a resistor and associated indication back contact for each switch and detector track section of the route.

A route selection circuit for route I from A to E, for example, will be completed if the leverman or operator in charge places levers K and K in their 1 positions and depresses push button to. This circuit passes from terminal a: of a suitable source of current, not shown in the drawing, through contact 219* in its right-hand position, resistor 320, back point of contact 32I winding of relay Q contact 322 winding of relay k front point of contact 325, winding of relay f front point of contact 326 winding of relay le front point of contact 328 winding of relay k contact 330, winding of relay y, front point of contact 332 winding of relay k front point of contact 334, winding of relay k winding of relay F, Winding of relay f front point of contact 336, Winding of relay k front point of contact 338*, winding of relay k resistor 3 13, and contact 219* to terminal 0 of the same source of current.

It will be noted that in this circuit the winding of each indication relay is for a switch or for a detector track section is in series with an indication front contact. The winding of relay k for section A-ii, for example, is in series with the front point of an indication contact 325. Each of the relays it for switches and detector track sections in this route will therefore be energized, causing the associated indicator lamps on the track model of Figs. 2 and 2 to become lighted, or causing the neon gas tubes on the track model of Fig. 3 to become energized. If relay U were deenergized, the route selection circuit under discussion would include resistor 324 and the back point of contact 325 instead of the winding of relay k and the front point of this contact, and hence relay k would be deenergized although other relays in the route selection circuit would still be energized. It is obvious that, if desired, separate front and back contacts of any given relay could be used instead of the front and back points of one contact, such as contact 325 of the same relay.

The route selection circuit which has been traced also includes the winding of a signal route relay designated by the reference character Q and would also include the winding of a signal indication relay Is upon energization of a signal selection relay designated by the reference character X Figs. 6 and 6 show signal selection circuits which become energized after corresponding signal route relays Q of Figs. 5 and 5 have become energized. Each of the signal selection circuits includes a signal selection relay designated by the reference character X with an exponent which includes the exponent of each signal which it con- .trols. Each of the signal selection circuits also aem e includes, in series with its signal selection relay X, a signal look relay designated by the reference character I with an exponent corresponding to that of the relay X for an opposing signal.

Fig. 7 shows circuits for the control of approach locking relays each of which is designated by the reference character P with an exponent which includes the exponent of each signal with which it is associated. Each approach locking relay P is so controlled that it becomes deenergized when any signal with which it is associated is controlled to permit a traffic movement.

Time releasing of approach locking relays P is controlled by the time releasing device J which may be of the normally unwound clockwork type. Group releasing of approach locking relays P is provided, that is, the one release J controls the releasing of all of the relays P.

Release J is equipped with two normally open contacts 259 and ZGB and withsix normally closed contacts 26W, 256 258 246%, 253"" and 255 Normally open contacts 259 and 24 6 can become closed only when release J is fully wound up.

In order to release any one of the approach locking relays P, time release J mustfirst be wound up to open the six normally closed contacts and to close the normally open contacts 259 and 24F and thereby cause the energization of one or the other, or both, of two slow-releasing relays N and NP, respectively. Relay N enters into' the control of approachlocking relays 19 and Pr, whereas relay N similarly enters into-the control of approach locking relays P and P When time release J is permitted to run down after being fully wound up, contacts 259 and MW willopen as release J leaves its'fully wound position, and contacts 265", NW, 253-l and 255, will close upon the lapseof a measured interval of .time after the beginning of theunwinding operation. Upon the lapse of a further measured period of time, contacts 26]?and 248 will also close.

' Control circuits for a call-on signal relay ZZ for signal 8 are also shown in Fig. 7. The control circuits for call-on signal relay ZZ for signal S are similar to those for relay 22 and are therefore omitted from the drawings.

In Fig. 8, circuits are shown for'relays, designated by the reference characters L and'L,

which are termed signal slotting relays. Relay L ente rs into the. control of signal S and relay L enters into the control of signal S. Fig. 9 shows circuits which constitute what is known as a signal control relay network. A signal control relay forcontrolling each signal, designated by the reference character Y with an exponent corresponding to that of its signal, is controlled by these circuits.

Having described, in general, the arrangement and operation of two forms of apparatus embodying our invention, we will now trace in detail the operation of these forms of apparatus.

As shown in the drawings, all parts of the apparatus are in the normal condition, that is, each track relay T is energized by a stick circuit including its front contact 39; each relay a is energized by a stick circuit passing from terminal a, through a contact MI of the associated relay 2 contact l t-2 of the relay a, and the winding of the relay 2 to terminal each lever K is in its normal position it; each push button to and each manually controlled contact u is in its open position; release J is in its normal position in wh ch it is shown in the drawing; each switch is in the normal position; each signal S is in its stop position; "each of the relays b, t, e f, g, k, Q, g, X, I, N, ZZ and Y is deenergized; and each indicator lamp e of Figs. 2 and 2 and neon gas tube 0 of Fig. 3 is extinguished.

With relay'T energized and with relay b deenergized, relay 12 shown in Fig. 1 is energized by a circuit passing from terminal .r, through the front point of contact 4| of relay T contact 42 of relay b and the winding of relay p to terminal o. Relays p to p inclusive, are energized by similar circuits, although the similar circuit is shown for only relay 10 With relays T and T energized and with relays 12 and 11 deenergized, relay 29 9* is energized by a circuit passing from terminal as, through the front point of contact 4 l of relay T contact 42 of relay b .43 of relay Tt", contact 42 of relay b the win dingof relay 12 9- to terminal 0.

With relay p energized, a pick-up circuit for r ayP of '7is closed, passing from terminal .iQthrbugh Contacts l5 lfi l'l and W and the winding of relay P to terminal 0. s ck circuit is alse closed for relay P and follows the path just traced for the pick-up circuit as far 'as eontact l 1 and thence passes through th t'poi'nt of cgntact IQ of relay P to the w nd ng "of relay P With relays 12 p and 12 energized, pickup as well as stick circuits are clg seicl forrelays P P and P respecti'v 1:}; Thes pick-up and stick circuits are similar t9 thc' sej sttraced for relay P and can therefore be readily traced on the drawing with-'- out further explanation.

relays p? and P energized, a pick-up circuit is closed for repeater stick relay U shown 'g. 1 passing from terminal as, through con- [lfi of relay p contact H8 and the winding of relay U to terminal 0. A stick circuit for relay U is also closed, passing from terminal 0:, through contact N5 of relay p contact I of relay U and the winding of relay U to terminal 0. Relay U is also energized by similar pick-up and stick circuits which, on account of the circuits for relay U having been traced, may be readily traced on the drawings.

With switch H in its normal position, switch indication relay h shown in Fig. l is energized in the normal direction by a circuit which includes pole-changer 5 of switch H in itsnormal position. With switches H and I-I in their normal positions, relay I1 is energized in the normal direction by a circuit which includes polechangers E and l of switches H and H respectively, in their normal positions. Circuits for energizing switch indication relays h? and h are similar to the circuits just described for relays h and M, respectively, and are therefore omitted from the drawing.

' Route locking relays V are energized by circuits which will be described hereinafter.

With relay V energized, and with relays 12 1 and e energized, a pick-up circuit is closed for relay R shown in Fig. l passing from terminal .2, through contacts M 45 and 46 winding of relay R contact 62 and contact 63 of relay m in its normal'or left-hand position to terminal o. A stick circuit for relay R is also closed, following the path just traced for the pick-up circuit as far as the winding of relay R and thence passing through contact 66 of relay R to terminal 0. A stick circuit is closed for relay R passing from terminal at, through contacts 538 49 5?), El and 52 winding of relay R and contact 66 of relay R to terminal o. A stick circuit is closed for relay R passing from terminal at, through contacts 53 54 55 56, 51 and 58 winding of relay R and contact 65 of relay R to terminal 0. A stick circuit is closed for relay R passing from terminal 11:, through contacts 59 60 and SI winding of relay R and contact '66 of relay R to terminal 0. A pick-up circuit is also closed. for each of the relays R R. and R following the stick circuit as far as the winding of each of these relays, andthence passing through a contact of an associatednormal switch stick relay 2 and a normal polar contact of'an associated polarized switch control relay m similarly to the pick-up circuit traced for relay R Each of the relays R has also a second pick-up circuit, normally open, which follows the path of the first pick-up circuit through the winding of the relay, and thence passes through a contact of an associated reverse switch control stick relay e and a reverse polar contact of an associated polarized.- switch control relay m. With relays 2 and R energized, a normal pick-up circuit is closed for relay m passing from terminal as, through the back point of contact 61 front point of contact 68 front point of contact H of relay R winding of relay 111., front point of contact 12 of relay R front point of contact 13 and the back point of contact M to terminal 0. relays m m and m are similar to the circuits for relay m and are therefore omitted from the drawings.

With relay m energized by current of normal polarity, normal control magnet 11.11. for motor M is energized by its circuit passing from terminal at, through contact H of relay m contact l2 of relay m in its left-hand position, and the winding of magnet 1m to terminal 0. The circuit for lock magnet q of motor M is, however, open at contact 211 of relay 2'', and hence motor M is deenergized. Relays m m and m are also energized by current of normal polarity, and therefore the normal control magnet 11.11. for motors M for each of the switches H H H H and H is also energized. The lock magnet q for these motors is, however, deenergized, and hence the motors for switches H H H H and H are also deenergizecl.

With relays h and m energized in the normal direction, a circuit is completed for energizing normal indication relay i passing from terminal in, through a resistor 26, contact 65 of relay m in its left-hand position, contact 69 of relay m contact 16 of relay t winding of relay 2', contact 18 of relay h in its left-hand position, and contact 19 of relay h to terminal 0. The circuits for energizing relay i 2' and i are similar to the circuit just traced for relay 2', and are therefore omitted from the drawings.

The circuits for energizing relays F, t and t are similar to the circuit shown, and which will be described hereinafter, for relay t and are therefore also omitted from the drawings.

With the various relays P, p, U and i energized, one or more pick-up and stick circuits are closed for each of the route locking relays V. For example, a pick-up circuit for relay V is closed, passing from terminal a;, through contacts BU 8I 83 84 85, and the winding of relay V to terminal 0. A second pick-up circuit is also closed for relay V which is the same as the pick-up circuit just traced except that it includes contact 82 insteadof contact 8 P. A third pickup circuit for relay V is also closed, and is the The circuits for energizing same as the first pick-up circuit except that it includes contact 86 instead of contact 85 A stick circuit for relay V is closed, passing from terminal [13, through contacts W and. 8N", contact 81 of relay V and the winding of relay V to terminal 0. A second stick circuit for W is also closed, and is the same as the first stick circuit except that it includes contact 82 instead of contact 8!.

On account of the various relays i, p and U being energized, each of the signal slotting relays L, shown in Fig. 8, is energized. The circuit for relay L passes from terminal :1:, through contacts H6 I21, IZB I29 I30, and l3l and the winding of relay L to terminal 0. Relay 1.- is energized by a similar circuit which may be readily followed on the drawings.

We will assume that the leverman or operator in charge desires to arrange for a traflic movement over route I from A to E. He will therefore move levers K and K to their right reverse positions r and depress push button 20 as previously described, thereby completing the route selection circuit previously traced in Figs. 5 and 5 Completion of this circuit causes energization of route stick relay y normal switch route relays f f and f signal route relay Q and indication relays k for each detector track section and switch of the route. Relay 3 upon becoming energized, completes its own stick circuit which is the same as the route selection circuit previously traced through the winding of this relay except that it includes contact 33l of relay 1/ instead of push button contact 330 On account of the normal indication relay i and the normal control stick relay 2 for each of the switches H 1-1 and H of the route being energized, and on account of relay P being energized, a circuit will be completed for energizing signal selection relay X and signal lock relay 1 as soon as relay Q closes its front contacts. This circuit passes from terminal at, through contact 389 of relay X contact 388 winding of relay I contacts 381 386 389*, 380 319 318 311 and 316, front point of contact 315 and the winding of relay X to terminal 0. T

With relay f energized, the pick-up circuit for relay 2 which includes contact M0 is closed. On account of relays f and i being energized, similar pick-up circuits are also closed for relays 2 and 2 Each of these relays is, however, already energized by its stick circuit.

Those indication relays k which are energized by the route selection circuit traced cause the energization of corresponding indicator lamps e of Figs. 2 and 2 or of corresponding neon gas tubes c of Fig. 3. Relay W, for example, upon becoming energized, closes its contact I53 which completes lighting circuits for lamps e and e for track section Az'i as shown in Fig. 2 or a circuit for energizing the neon gas tube 0 as shown in Fig. 3; and relay k upon becoming energized, closes its contact 55 for lighting the lamp eH211 of Fig. 2 or for energizing the neon gas tube c of Fig. 3.

On account of relay X being energized, its contact MP in the route selection circuit previously traced will open its back point and close its front point, thereby causing indication relay 70 to become energized. With relay I0 energized, indicator lamp e associated with signals S will be lighted by its circuit passing from ter- -minal as, through contact l52 and lamp e to terminal 0-.

The energization of relay X causes its contact I13} to open, thereby deenergizing approach locking relay P Relay P upon becoming deenergized, opens, at its contact 56 the pick-up and stick circuits for relay R causing this relay to also become deenergized. Relay P upon becoming deenergiz ed, also opens its contact 88*, causing relay V to become decner'gized.

Relay V upon becoming deenergized, opens its contacts and 45" in the pick-up and stick circuits for relays R and R respectively, causing both these relays to become deenergized.

Relay R upon becoming deenergized, opens, at the front points of its contacts H and 12, the

normal energizing circuit previously traced for relay m and then closes, at the back points of these contacts, a normal stick circuit for relay m passing from terminal :0, through resistor 26, contact 65 of relay m in its left-hand position,

contact 69 of relay 112 back point of contact H of relay R winding of relay 112 back point of contact 12 of relay R contact ill of relay m and contact 63 of relay m in its left-hand position to terminal 0. Relays R and R upon becoming deenergized, similarly open normal energizing circuits for relays m and m and close normal stick circuits for these relays. Therefore, as long as relays R R and R remain deenergized, the direction of energization of relays 111. m and or cannot be changed, but these relays will be retained energized in the normal direction by their normal stick circuits.

Relay P upon becoming deenergized, opens its contact M in various circuits for relay V but this relay will be retained in its energized condition by circuits through contact 82 Relay P upon becoming deenergized, also opens its contact H6 in the pick-up circuit for relay U which, however, remains energized by its stick circuit previously traced.

With relays R R R and V deenergized, and with relay X energized, a circuit is completed for energizing signal control relay Y this circuit passing from terminal :L', through contacts I'I5 Ilii back point of contact H1 B I'll), new, ltil M33 and Ite front point of contact 33 contacts 186 H37 I88, and I89, contact Hill of relay Y and the winding of relay Y to terminal 0. Relay Y upon becoming energized,

opens its back contact.

NW in the circuits for approach locking relay P which, however, have already been opened at contact 11 Relay Y upon becoming energized, causes the armor signal S to be operated to the proceed position by its circuit passing from terminal 3:, through contact 23W, and the mechanism of signal S to terminal 0.

We will now assume that, with signal S indicating proceed for a traflic movement over the route from A to E, an eastbound train arrives on approach section a-A, and that the operator then desires to stop the train at signal El and send it over some other route than that from A to E. The train, upon entering section a-A, causes relay T to become deenergized and open its contact M at the front point, which thereupon causes relay p to also become deenergized. With relay p deener'gized, lamp e of Fig. 2 or neon gas tube 0 of Fig. 3 will be lighted by a circuit which includes contact lfii return lever K to the normal position, causing all relays of the route selection circuit previously traced in Figs. 5 and 5 to become deenergized. All the lights for the route from A to E, controlled by indication relays is, will therefore become ex- The operator will tinguished. With relay Q deenergiz ed, the circuit previously traced for relay X will be open at the front point of contact 315 and hence relay X will also be deenergized. With relay X deenergized, contact I85 in the circuit traced for relay Y will be open at its front point, and hence relay Y will be deenergized. The arm of signal S will therefore move to its stop position.

On account of the train which occupies approach section aA causing relay p to be deenergized, relay P cannot become energized by its pick-up circuit which includes contact 18 when the leverman returns lever K to its normal position. In order to energize relay P the operator will then wind release J, causing its normally closed contacts 243, 253 255, 261 266 26t to open, and causing its normally open contacts MW and 259 to close. Contact 245i will now complete a pick-up circuit for energizing relay N this circuit passing from terminal .13, through contacts M ifi IE I'I back point of contact is of relay P front point of contact 245 of relay 1 contact 246-, and the winding of relay N to terminal 0. Relay N upon becoming energized, will complete its stick circuit which is the same as the pickup circuit just traced except that it includes contact 24? of relay N instead of contact 246-.

After having wound release J to close contact 246 the operator will permit release J to start its unwinding operation. Contacts 24W and 259 will open as soon as the unwinding operation starts. Upon the lapse of a measured period of time after the beginning of the unwinding operation, contacts 253, 255 28t and 26B will close, but the closing of these contacts will not complete a pick-up circuit for relay P Upon the lapse of a further measured period of time, contacts 2 w and 26]" will close.

Contact 2i thereby completes a pick-up circuit for relay P following the path of the pickup circuit previously traced for relay P as far as contact IF, and thence passing through contact 2453*; contact 254 of relay N and the winding of relay P to terminal o Relay P upon becoming energized, will complete its stick circuit previously traced. Relay P upon becoming energized, opens, at the back point of its contact 19, the stick circuit for relay N which is thereby deenergized.

Relay P upon becoming energized, completes, through its contact 56 the first pick-up circuit for relay R which becomes thereby energized. Relay P also closes its contact 88 in the pick-up circuit for relay V causing relay V to also become energized. Relay V upon becoming energized, completes, at its contacts 41 and 45 the first pick-up circuits for relays R and R, causing these relays to again become energized.

The operator will now move lever K to its r position in order to complete the route selection circuit for route 2 from A to F. This circuit follows the path previously traced for the route selection circuit for route I from A to E as far as the winding of relay f and thence passes through the winding of relay 9 back point of contact 344t resistor 845, front point of con.- act 345 winding of relay k resistor 355i, and contact 2W to terminal 0.

With this route selection circuit closed, normal switch route relays and f will be energized, but relay f will now be deenergized', and reverse switch route relay Q will be energized. Relay g upon becoming energized, completes a circuit for energizing the reverse switch control stick relay a, which is similar to the circuit including contact |43 for energizing relay 2. Relay 2, upon becoming energized, opens, at its contact Ml, the stick circuit for relay 2 causing relay 2* to be deenergized.

Relay Q will now be energized by the route selection circuit traced for route 2.

The circuit previously traced for relay X will be open at contact 389 and the branch path for the circuit for relay X through contacts 383 and 382 will be open at contact 381% until switch H moves to its reverse position in response to the energization of relay 2.

With relays z and R energized and with relay e deenergized, the reverse energizing circuit for relay m will be completed, passing from terminal 3:, through the front point of contact 61 back point of contact l3 n, front point of contact 12 of relay R winding of relay m in multiple with resistor #5, front point of contact ll of relay R back point of contact 68 and the front point of contact i4 to terminal 0.

As soon as relay m reverses its contact 65, a second pick-up circuit will be completed for relay R, which is the same as the pickup circuit previously traced for this relay as far as its winding, but which then passes through contact 64 and contact 65 of relay m in its right-hand position to terminal 0. With relay m energized in the reverse direction, the circuit previously traced for relay 1? will be opened at the left-hand position of contact 55, and hence relay i will be deenergized.

With relay 1' deenergized, a circuit is now completed for lock magnet q of switch motor M passing from terminal at, through contact 211 of relay i contact 218 of relay t and magnet q to terminal 0. With relay m energized in the reverse direction, a circuit is completed for energizing magnet 17' of switch motor M passing from terminal as, through contact ll of relay m contact l2 of relay m in its right-hand position, and the winding of reverse magnet To" to terminal 0. With lock magnet q and reverse magnet rr energized, motor M will move switch H to its re verse position, causing pole-changer 5 to be reversed.

Pole-changer 5, upon becoming reversed, causes relay it to be energized in the reverse direction, thereby completing a circuit for reverse indication relay t passing from terminal 1:, through resistor 26, contact 63 of relay m in its righthand position, contact l0 of relay m contact 71 of relay i winding of relay t contact 178 of relay h in its right-hand position, and contact 19 of relay 71 to terminal 0. Relay t upon becoming energized, opens, at its contact 278, the circuit traced for lock magnet q of motor M Relay upon becoming energized, completes a second circuit for relay X which is the same as the circuit previously traced for this relay except that it includes the branch path through contacts 383 and 382 instead of the path through contacts 38 I and 388 Relay X upon becoming energized by this circuit, completes a circuit for energizing relay Y which, except that it includes contact Hill instead of contact H9, is the same as the circuit previously traced for relay Y as far as contact H21 thence passing through contact I9 3, contact I91 of relay Y contact I98 of relay Y, and the winding of relay Y to terminal 0. With relay "5? energized, the arm of signal S will be operated to its proceed position by a circuit passing from terminal at, through contact 23W, and the mechanism of signal S to terminal 0.

We will now assume that all parts of the apparatus have again been returned to the normal condition, and that the operator then clears signal S for a traffic movement from A to E. We will also assume that the operator clears signal 5 for a traflic movement from D to B. The operation of the apparatus for clearing signal S is similar to that previously described for signal S, and may therefore be readily followed from the drawings.

We will assume that an eastbound train enters approach section a-A, and that the operator then decides to send the train over the route from A to F. He will, therefore, return the arm of signal S to its stop position, and will then wind up release J and start its unwinding operation as previously described.

We will further assume that after relay N becomes energized, but before relay P becomes energized, a westbound train enters section vi -d and that the operator then decides to send the westbound train over the route from D to C. He will therefore return the arm of signal S to its stop position, and will then either wait for release J to close its contact 248 for energizing relay P before he winds up the release, or he will at once wind up the release, causing relay N to become energized by a circuit passing from terminal a:, through contacts 33 34 35 and 35*, back point of contact 38 of relay P front point of contact 258 of relay 1 contact 259 of release J, and the winding of relay N to terminal 0. Relay N upon becoming energized, completes its stick circuit which is the same as the pick-up circuit just traced except including its contact 250 instead of contact 259 of release J.

The operator will then permit release J to again unwind. Upon the lapse of a measured period of time after the beginning of the unwinding operation, both contacts 248 and 26 l of release J will close, causing relays P and P respectively, to become energized. The operator can then cause switches H and H to be reversed as previously described for switch H We will next assume that the operator returns the apparatus to the normal condition, and that he then again clears signal S for a traffic movement from A to E. We will also assume that an eastbound train passes through approach section a--A into section A- -ii. The train, upon entering section Aii, deenergizes relay T which opens its contact All at the front point and causes relay p to also become deenergized. Relay :0 upon becoming deenergized, permits its contact I I5 to open and thereby deenergize relay U Relay p upon becoming deenergized, also opens its contact 92 thereby preventing ener ization of relay V as long as the train occupies section A2'2'.

Relay U upon becoming deenergized, drops its contact 325 from the front point to the back point, thus deenergizing indication relay k in the route selection circuit previously traced for the route from A to E in Figs. 5 and 5 Relay k upon becoming deenergized, permits its contact i53 to open the circuit for indicato lamps e and c of Fig. 2 or for neon gas tube c of Fig. 3. In this way, the operator is informed that the train has entered section Aii.

Relay U upon becoming deenergized, also opens, at its front contact H8 the circuit traced for relay L causing relay L to become energized. Relay L in turn opens its contact l89 causing relay Y to become deenergized.

The arm of signal S thereupon returns to the stop position because of the opening of contact 231".

As soon as the operator now returns either lever K or K to its n position, causing relay Q to become deenergized and in turn also causing relay X to become deenergized, a circuit will be completed for energizing relay P of Fig. 7, passing from terminal :1:, through contacts M I5 IB and W back point of contact 249 of relay ZZ contact 250 and the winding of relay P to terminal 0.

The train, upon entering section ii-y'a, causes relay T to become deenergized, which in turn causes relay p to become deenergized. Relay p upon becoming deenergized, will open its contact 94 in the pick-up circuits for relay V, thus preventing this relay from becoming energized when the train leaves section A-ii and permits relay p to close its contact 92 Relay p upon becoming deenergized, permits its contact 332 in the route selection circuit previously traced for the route from A to E to open at its front point and to close at its back point,

thereby deenergizing indication relay k Relay k upon becoming deenergized, permits its contact I53 to open the circuit for either lamp e of Fig. 2 or a corresponding neon gas tube similar to those shown in Fig. 3.

When the train leaves section A-ii, relay U will become energized by its pick-up circuit previously traced, permitting relay R to again become energized by its first pick-up circuit. Relays R and R however, will remain deenergized while relay V is deenergized.

Relay V will remain deenergized until the train leaves section ii-q7', whereupon relay V will become energized by its pick-up circuit passing from terminal at, through contact 88 contact Bil in multiple with contact 9!, contacts 92 and M and the winding of relay V to terminal o. Upon the energization of relay V relay R will become energized by its first pick-up circuit.

Relay R will, however, remain deenergized un.

til the train has passed out of section iii-E and has thus permitted relay p to complete the first pick-up circuit for relay R*.

If the operator permits levers K and K to remain in their reverse positions to the right, a train, upon entering each succeeding track section, will cause the corresponding track section indication relay is to become deenergized and will thus cause the corresponding indicator lamps e of Figs. 2 and 2 or the corresponding neon gas tubes of Fig. 3 to be deenergized. As soon as the train passes outof each section while levers K and K are left in their r positions, the corresponding indication relay is will become energized and will thereby cause the associated indicator lamp e of Fig. 2 or 2 or the associated neon gas tubes 0 of Fig. 3 to again be energized.

We will assume that all parts of the apparatus are again in their normal condition, and that the operator clears signal S for a train to move over route I from A to E. We will further assume that after a train has passed signal S, but before it has passed point E, the operator desires to permit a second train to pass point A. He will therefore depress push button shown adjacent the representation of signals S in Figs. 2 and 3, thereby completing a pick-up circuit for energizing callon relay Z2 this circuit passing from terminal as, through contacts I38 [39 214 and the winding of relay ZZ to terminal 0. Relay P of Fig. 7 is deenergized on account of relay X being energized, and hence a stick circuit for relay ZZ will be completed, passing from terminal as, through contact 212 contact 213 of relay ZZ contact 214 and the Winding of relay ZZ to terminal 0.

With relay ZZ energized, a circuit will be completed for energizing relay Y which is the same as the circuit previously traced for this relay as far as contact I86 thence passing through contact IQG contact I91 of relay Y contact I98 of relay Y and the winding of relay Y to terminal 0. With relay Y energized, the arm of signal S will be caused'to display a. call-on indication by its circuit previously traced through contact 23l We will next assume that all parts of the apparatus are again in their normal condition, and

that the operator desires to arrange for a westbound train movement from E to A. He will therefore move levers K and K to their leftreverse positions 12.

A route selection circuit will thus be completed, passing from terminal cc, through contact 2'19 in its left-hand position,resistor 323, winding of relay k and thence by the path previously traced for the route selection circuit for a traffic movement from A to E as far as the winding of relay It, and then passing through contact 340 winding of relay Q back point of contact 34I resistor 342 and contact 219 in its left-hand position to terminal 0. With this circuit closed, the indication relays It for the detector track sections and for the switches in the route will again be energized, causing the corresponding lamps e of Figs. 2 and 2 or the neon gas tubes 0 of Fig. 3 to again become energized.

It will be noted that the winding of relay Q is included in this circuit, whereas in the route selection circuit for a traflic movement from A to E, the winding of relay Q was included. Relay Q upon becoming energized, completes a circuit for energizing relaysI and X passing from terminal 0:, through contact 313 of relay X contact 3'M winding of relay I back point of contact 315 contacts 316 311 318 319 380 38! and 3B4 and the winding of relay 21 to terminal 0.

Relay X upon becoming energized, causes indication relay it in the route selection circuit to become energized and complete a circuit for energizing signal control indication lamp e of Fig. 2 Relay X upon becoming energized, opens, at its contact 23 the pick-up and stick circuits for approach locking relay P causing relay P to become deenergized.

Relay P upon becoming deenergized, opens its contacts l05 and I IP545 in the circuits for route locking relays V and V respectively, causing these relays to become deenergized. With relay P deenergized, its contact 46 will open the circuits for relay R causing relay R to become deenergized. With relay V deenergized, its contact 53 will be open in the circuits for relay R causing relay R to become deenergized, and with relay V deenergized, its contact 49 will be open in the circuits for relay R causing relay R to also be deenergized,

With relays V R R and R deenergized, and with relay X energized, a circuit will be completed for energizing relay Y passing from terminal at, through contacts IBS 200 IBA [83 I82 l8l H9 and "8 front point of contact IH contacts 2M and 202 contact 203 of relay Y and the winding of of the route selection circuit traced for the traffic movement from E to A to become deenergized. The deenergization of the indication relays It will cause the corresponding lamps e of Figs. 2 and 2 or neon gas tubes 6 of Fig. 3 to become deenergized. With relay Q deenergized, relay X will become deenergized, and relay X upon becoming deenergized, will open the circuit.for relay Y at the front point of contact lTl causing relay Y to become deenergized.

Upon thedeenergization of relay the arm of signal S will be returned to its stop position. On account of the westbound train occupying section EE relay 1 will be deenergized, and

hence contact 24 will be open in the normally closed pick-up circuit for approach locking relay In order to cause energization of relay P the operator will now again wind release J. When release J is fully wound up, relay N will be energized by a second pick-up circuit passing from terminal at, through contacts 22 and 23 back point of contact 2&5 of relay P contact 246 and the winding of relay N to terminal 0. Relay N upon becoming energized,

completes a stick circuit which is the same as the pick-up circuit just traced except that it includes front contact 247 of relay N instead of contact 246 As soon as release J is fully wound up and relay N is operated, the operator will permit the unwinding operation of this release to begin. Contacts 2 H; and 259 will then open, and upon the lapse of a measured interval of time, contacts 266 268 253 and 255 will close. Contact 255 upon becoming closed, completes a pick-up circuit for relay P passing from terminal at, through contacts 2D, 22, 23 and 255 contact 256 of relay N and the winding of relay P to terminal 0.

Relay P upon becoming energized, open at the back point of its contact 245, the stick circuit previously traced for relay N Relay N being slow-releasing, retains its front contacts closed long enough for relay P to complete its stick circuit which is the same as the pick-up circuit traced for relay P as far as contact 23 thence passing through contact 25 of relay P and the winding of relay lP to terminal 0. Relay P upon becoming energized, completes, at its front contact 4G the first pick-up circuit previously traced for relay R Relay P upon becoming energized, also completes a pick-up circuit for relay V passing from terminal as, through contacts Mi H2 and H3 and the winding of relay V to terminal 0. Relay V upon becoming energized, completes its stick circuit passing from terminal 1', through contact HI contact lid of relay V, and the winding of relay V to terminal 0. Relay P upon becoming energized, also completes a pick-up circuit for relay V passing from terminal :0, through contact i%5 contact HJT in multiple with contact 108, contact lflfl and the winding of relay V to terminal 0. Relay V upon becoming energized,

completes a stick circuit which is the same as the pick-up circuit just traced except that it includes contact HE! of relay V instead of contact Nil-2 Upon the energization of relays V V relays R and R respectively, become energized by their first pick-up circuits. With relays R R and R again energized, the operator can now arrange some other route for the westbound train,

We will assume that all parts of the apparatus have been again returned to the normal condition, and that the operator then desires to arrange for a run-around train movement over route 3 from A to E by reversing switches H H H and H and retaining switch H in its normal position. Ie will therefore move levers K and K to their right reverse positions 7, and will depress push button w thereby completing a route selection circuit passing from terminal at, through contact 279 in its right-hand position, resistor 326, back point of contact 32l winding of relay Q contact 322 winding of relay k front point of contact 325, winding of relay Fe contacts 3! W and M2, resistor 3|3, back point of contact 3H5, winding of relay 9 contact 398 winding of relay 11 winding of relay 9 back point of contact 315, resistor SIG, front point of contact 3H front point of contact 1358, winding of relay lb winding of relay f front point of contact 336 winding of relay la front point of contact 333 winding of relay lc resistor 343, and contact 2T9 in its right reverse position to terminal 0. This circuit, upon being completed, energizes reverse switch route relays 9' and g and normal switch route relay f as well as indication relay k but does not energize indication relays k and k until switches H H and H H respectively, have moved to their reverse positions in response to the energization of relays g and g Relays g and 9 upon becoming energized, cause relays 2 and a to become energized, and switches H H and H H, upon being operated to their reverse positions, cause relays t2 and t to become energized.

As soon as relays t and t become energized relays k and R will become energized and cause the corresponding indicator lamps e of Figs. 2 and 2 or neon gas tubes 0 of Fig. 3 to become energized. As soon as relays t and t have become energized, a third circuit will be completed for energizing relays I and X passing from terminal x, through contact 389 of relay X contact 388 winding of relay 1 contacts 33 BBS 383, 382 312, 311 310 ttt front point of contact 315 and the winding of relay X to terminal 0.

Relay X upon becoming energized, opens its contact l'l thereby deenergizing approach locking relay P as previously described. Relay X upon becoming energized, also opens its contact 32 P at the back point and closes this contact at the front point, thereby causing signal control indication relay k to become energized. Relay k upon becoming energized, closes its contact itil thus causing lamp e of Fig. 2 to become lighted as previously described.

Relay P upon becoming deenergized, permits its contact 88 to open, thereby deenergizing relay V as previously described. With relays P and V deenergized, relays R R and R will be deenergized as also previously described, thus preventing change in direction of energization of relays; m ,.m and m As soon as relays R R and R become deenergized, a third circuit will be completed for energizing signal control relay Y this circuit passing from terminal through contacts "E |'|6 back point of contact fil I18 mo 20W, ZIl'i 2m Zllli and I84 front point of contact H35 contacts I86 NH, and I95, contact l9! of relay Y contact I98 of relay SW, and the winding of relay Y to terminal 0. With relay Y energized, the arm of signal S will be operated to its proceed position by its circuit including contact 231 We will now assume that all parts of the apparatus are again returned to the normal condition, and that the operator then desires to arrange the switches for a trafiic movement over route 3 from A to D, but that he desires to hold all signals in the stop position. This can be accomplished by any one of three methods, namely:

1. By moving lever K to the left, and lever K to the right.

2. By moving lever K to the right, and lever K to the left.

3. By controlling the track switches individually, by operation of the manual control contacts it. Since switch H is already in the normal position, it will only be necessary to close manually controlled contact n for causing switches H and H to be reversed.

If the operator uses either the first or the second method, the indicators for the detector track sections and the switches of the route will become energized, Whereas if he uses the third method, closing contact a the indicators will not be energized.

If the operator uses the first method for arranging the switches for the route from A to D and at the same time holding the signals in the stop position, he will complete a circuit passing from terminal at, through contact l!!! in the left reverse position, resistor 323, winding of relay k front point of contact 325 winding of relay 70 front points of contacts 3! W and M2, resistor 3l3, back point of contact 3l4 winding of relay g push button contact 300 winding of relay y winding of relay f, front point of contact 302 winding of relay Is front point of contact 3M winding of relay k resistor 309,-

and contact 2'19 in its right-hand position to terminal 0. It will be noted that, by this circuit, ys k 7 9 W, I, la and k will be energized. The indicators controlled by the energized relays It will thereupon become energized. With relay 9 energized, relay 2 will become energized and 2 will become deenergized, causing relay m to be energized in the reverse direction, which in turn will cause switches H and H to be operated to their reverse positions. With these switches in their reverse positions, relay t will become energized and will thus complete, at the front point of its contact 3|4 the path through winding of relay k causing the indicator e controlled by this relay to become energized. Since the signal route relays Q and Q for the two ends of this route are deenergized, neither relay X nor X will become energized, and hence neither signal S nor signal S will be cleared.

If the operator uses the second method by moving lever K to the right reverse position and lever K to the left reverse position, the operation of the switches and indicator lamps will be accomplished as just, described, but the route selection circuit by which this is accomplished will now pass from terminal :0, through contact 219 in its right-hand position, resistor 32!), back point of contact 32l winding of relay Q contact 322 winding of relay 70 and thence by the path previously traced for the first method as far as the winding of relay k thence through contact 306 winding of relay Q back point of contact 301 resistor 308, and contact 219 in the lefthand position to terminal 0. Since both relays Q and Q are now energized, contacts 3'I5 and 366 will both be closed at their front points, and hence no current can flow from terminal :0 through either relay X or X and therefore signals S and S for the route will both remain in the stop position as before.

If the operator uses the third method for arranging the route from A to D, he will cause relay 2 to be energized by a circuit passing from terminal 1:, through contact a, and the winding of relay a to terminal 0. Relay 2 upon becoming energized, will open its contact I4 I, thereby causing relay 2? to become deenergized. With relay z energized and. relay e deenergized, the winding of relay m will be energized in the reverse direction, and switches H and H will therefore be operated to their reverse positions. Indication relays It will, however, remain deenergized, and hence none of the indicators 6 of Figs. 2 and 2 nor 0 of Fig. 3 will be energized.

We have described, for a few typical traffic movements, the operation of two forms of apparatus embodying our invention. From those descriptions of operation and from the preceding general description, operation of each of the two forms of apparatus for every other possible traffic movement will be readily understood by reference to the drawings.

Apparatus embodying our invention although adapted to control any track layout likely to be encountered in practice is shown for convenience arranged to control a layout similar to that shown in the Spray application hereinbefore referred to, including switches which can be arranged for eleven different routes. Traffic movements can be made in either direction over each of these routes.

One form of apparatus embodying our invention includes a track model and interlocking control board, shown in Figs. 2 and 2*, having mounted in the tracks of the diagram diiferent series of lamps e for indicators. A second form of apparatus embodying our invention differs from the first form only by including a track model and interlocking control board, shown in Fig. 3, on which are provided indicators of linear form comprising neon gas tubes 0 for indicating a route by a. substantially continuous line instead of by a series of points as when the lamps e shown in Figs. 2 and 2 are employed.

In each of these two forms of apparatus, shown in the accompanying drawings, a manually operable control lever or route button of the rotary type is provided for each route end or signal location. Manually operable push button circuit controllers are also provided for points intermediate the opposing signals when the track layout provides alternative routes between the same route ends and run-around traffic movements are to be arranged for. Each control lever has three positions, comprising a normal or middle position n, a reverse position to the right r for arranging the switches and for clearing the eastbound signal for the route, and a. reverse position v to the left for arranging the switches for the route and for the clearing of the west bound signal for the route.

In order to arrange the switches of each route in the positions required for the route and in order to clear the eastbound signal for the route, the operator will place the two levers for the route in their right reverse positions and depress the intermediate push button to for the route. Similarly, in order to arrange the switches of each route in the positions required for the route and in order to clear the westbound signal for the route, the operator will place the two levers for the route in their left reverse positions and depress the intermediate push button w for the route. In order to arrange the switches of each route in the positions required for the route but to hold the signals for the route in the stop position, the operator will place the levers for the two ends of the route in opposite positions, that is, one lever will be placed in the left reverse position, while the other is placed in the right reverse position, and the push button for the intermediate point of the route will be depressed.

Separate normal and reverse manual control devices u are provided for each single switch and for each pair of crossover switches for separately causing operation of the corresponding single switches and pairs of crossover switches.

The indicators e provided on the control board shown in Figs. 2 and 2 and the indicators 0 provided on the control board shown in Fig. 3

are normally deenergized. The indicators for the detector track sections in a route and for each switch already occupying the required position will become energized as soon as the operator arranges the levers for the two ends of the route which he desires to set up, so that an illuminated line or series of lights will appear on the track diagram to correspond with the proposed route, with a gap in the illumination at the location of each switch which requires to be operated to a difierent position. As the switches complete their operation, the gaps are filled in, so that a substantially continuous line or a full series of lights appears when the route is fully established, at which time the indicator for the signal at the entrance to the route is also lighted, provided the levers have been moved to corresponding positions in orde' to clear the signal. The indicator lamps associated with the signals governing traiiic movements from right to left can become energized only when the operator arranges both levers for the route in their left reverse positions, while those for signals governing traffic movements from left to right can become energized only when the operator places both levers for the route in their right reverse positions. When a train enters an established route the continuity of the illuminated line or series of lights is again interrupted, the switch section and entrance signal lamps remaining lighted while the lamps for each track section are extinguished as long as the train occupies such section, thereby indicating the progress 0? the train over the route, the illumination of all sections of the representation of the route being cancelled upon the restoration of the route levers to normal.

Although we have herein shown and described only two forms of interlocking control apparatus embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is:

1. In an interlocking control system for a plurality of railway tracks interconnected by switches to form a plurality of routes, a normal and a reverse control relay for each of said switches, a manually operable lever for each route end, a route relay for each route end, a plurality of circuits corresponding to said routes one for each direction of traffic movements over each of said routes and each of which includes in series the control element of the normal or the reverse control relay for each switch in the corresponding route and also a contact controlled by the manually operable lever for each end of the route as well as the control element of the route relay at the end of the circuit which corresponds to the entrance end of the route for the direction of traflic movements with which the circuit is associated and also a source of current for operating the relays of the circuit, means controlled by the normal and reverse control relays for each switch for operating the corresponding switch to normal and reverse positions respectively, a signal for each route end, and means controlled by said route relays for operating said signals.

2. In combination, a plurality of railway tracks interconnected by switches to form a plurality of routes, a signal for each direction of traffic movements over each of said routes for governing traffic movements in the corresponding direction over each route, a manually operable route lever for each route end having a first and a second position, means controlled by both levers for each route for arranging the switches of the corresponding route so that each switch will be in the position required by the route if both levers are placed in the first position or if both levers are placed in the second position as well as if one of said levers is placed in the first position and the other is placed in the second position, means controlled by both levers for each route for clearing the signal for one direction of traffic movements over the route if and only if both levers are placed in the first position, and means controlled by both levers for each route for clearing the signal for the opposite direction of trafiic movements over the route if and only if both levers are placed in the second position.

3. In an interlocking control system for a plurality of railway tracks interconnected by switches to form a plurality of routes, a normal and a reverse control relay for each of said switches, it normal and a reverse indication relay for each of said switches, a normal and a reverse contact for each switch each controlled by its switch in the corresponding position, a plurality of interconnected circuits each of which corresponds to one of said routes and each of which includes either a normal control relay in series with a normal indication relay and a normal contact or a reverse control relay in series with a reverse indication relay and a reverse contact for each switch in its route and also includes a manually controlled contact and a source of current for operating the relays in the circuit, means controlled by the normal and reverse control relays for each switch for operating the corresponding switch to normal and reverse positions respectively, and normal and reverse indication means for each switch controlled by the normal and reverse indication relays for the same switch in accordance with the condition of the normal and reverse contacts respectively for that switch.

4. In an interlocking control system for a plurality of railway tracks interconnected by switches to form a plurality of routes, a normal 

